1. Field of the Invention
The present invention relates to a sheet container such as a sheet re-feeding device of a duplex/composite copy for containing/aligning sheets transported from the image forming portion of an image forming device, or a finisher and the like for binding sheets.
2. Description of the Prior Art
Recently, various sheet re-feeding devices are provided which temporarily contain a copy paper with an image formed on one side and thereafter re-feed the same to an image forming portion for obtaining a duplex copy or a composite copy. In such sheet re-feeding device, a regulating plate can be automatically set at a position corresponding to the size of the copy paper in order to align the contained copy paper.
However, in such device, when a paper jamming or the like occurs and the sheet re-feeding device is opened, the regulating plate may be moved erroneously or on purpose by the operator in removing the jammed paper. Generally, the regulating plate is driven by a stepping motor. However, the modulating ratio of the gear mechanism is not very large and there is no locking mechanism, so that it can be easily moved by an external force. Therefore, there is a possibility of starting a copying operation with the regulating plate moved from the normal position, in which case the sheet may not be contained properly, or may not be fed properly, causing jamming, skew and so on.
U.S. Pat. No. 4,123,155 discloses a copy machine for duplex copy in which a duplex copy mode is automatically selected if a sheet exists in an intermediate tray when the power is turned on. The operator can override the automatically set duplex copy mode and when overridden, the sheet in the intermediate tray is discharged out of the machine without any image formed thereon (see column 5, lines 34 to 55).
U.S. Pat. No. 4,657,239 discloses a sheet aligning device applied to an intermediate tray used in, for example, duplex copying machine.
Japanese Patent Laying-Open Gazette No. 38760/1984 discloses a duplex copying machine in which the copy mode is changed from duplex to one side if a sheet is remaining in an intermediate tray and when the copy switch is turned on, the remaining sheet is discharged.
U.S. Pat. No. 4,702,589 discloses a duplex copying machine provided with an intermediate tray having a sheet aligning means.
U.S. Pat. Nos. 4,365,886 and 4,568,169 disclose a duplex copying machine with an intermediate tray detachable to the body.
However, any of the above described patents do not disclose resetting of the aligning mechanism when the intermediate tray is attached, nor the discharging of the remaining sheet in the tray in response to the attachment.